CN116917584A

CN116917584A - Electric working machine

Info

Publication number: CN116917584A
Application number: CN202280016767.6A
Authority: CN
Inventors: 金田健佑; 鬼束讲介
Original assignee: Yanmar Holdings Co Ltd
Current assignee: Yanmar Holdings Co Ltd
Priority date: 2021-02-24
Filing date: 2022-02-02
Publication date: 2023-10-20
Also published as: JP2024028511A; EP4299843A1; WO2022181271A1; JP2022129045A; US20240125093A1; KR20230147609A; JP7423565B2

Abstract

The hydraulic excavator as an electric work machine includes: a charger for charging the battery by supplying power from an external power source to the battery; an electric motor driven by electric power supplied from a battery; a hydraulic system including a hydraulic pump driven by the electric motor and a hydraulic actuator supplied with pressure oil by the hydraulic pump; a control unit that manages, as first operation information, a physical quantity indicating an operation state of the electric motor, and manages, as second operation information, a physical quantity indicating an operation state including charge and discharge of the battery; and an output unit that outputs the first operation information and the second operation information.

Description

Electric working machine

Technical Field

The present invention relates to an electric work machine.

Background

Conventionally, a maintenance time notification device for a construction machine has been disclosed. For example, in the notification device of patent document 1, the driver or the manager is notified of the information that the actual operation time of the engine reaches the maintenance time for each maintenance item.

Patent document 1: japanese patent laid-open No. 2007-2626806

In recent years, in addition to a hydraulic excavator that drives a hydraulic actuator by power of an engine, a hydraulic excavator (electric excavator) that drives a hydraulic actuator by power of a battery is widely used. In an electric excavator, an electric motor is driven by electric power from a battery to rotate a hydraulic pump, and pressure oil is supplied to a hydraulic actuator to drive the hydraulic actuator.

In the electric excavator, the hydraulic pump is driven by the electric motor as described above, so the operation time of the electric motor can be regarded as the operation time of the hydraulic pump. Therefore, by managing the operation time of the electric motor, the maintenance period of the hydraulic system including the hydraulic pump can be managed, whereby the maintenance of the hydraulic system can be performed at an appropriate timing.

On the other hand, the battery also deteriorates during charging, not only during discharging, i.e., during operation of the electric motor. Therefore, if the maintenance time is managed based on the operation time of the electric motor as in the hydraulic system, the battery cannot be maintained at an appropriate timing in which degradation in battery charging is also considered.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an electric working machine capable of performing maintenance of a hydraulic system and a battery at appropriate timings, respectively.

An electric work machine according to one aspect of the present invention includes: a charger for supplying power from an external power source to a battery to charge the battery; an electric motor driven by electric power supplied from the battery; a hydraulic system including a hydraulic pump driven by the electric motor and a hydraulic actuator supplied with pressure oil from the hydraulic pump; a control unit that manages a physical quantity indicating an operation state of the electric motor as first operation information, and manages a physical quantity indicating an operation state including charge and discharge of the battery as second operation information; and an output unit configured to output the first operation information and the second operation information.

According to the above configuration, maintenance of the hydraulic system and the battery can be performed at appropriate timings, respectively.

Drawings

Fig. 1 is a side view showing a schematic configuration of a hydraulic excavator, which is an example of an electric working machine according to an embodiment of the present invention.

Fig. 2 is a block diagram schematically showing the configuration of the control system and the hydraulic system of the hydraulic excavator.

Fig. 3 is an explanatory view showing an example of a display on the display unit of the hydraulic excavator.

Fig. 4 is an explanatory diagram showing another example of the display on the display unit.

Fig. 5 is an explanatory diagram schematically showing an example of the energization state of the relay, the operation state of the electric motor, the operation state of the charger, and the operation state of the battery in each of the charging mode and the battery mode.

Fig. 6 is an explanatory diagram schematically showing an example of the energization state of the relay, the operation state of the electric motor, the operation state of the charger, and the operation state of the battery in each of the charging mode, the battery mode, and the power supply combined mode.

Detailed Description

Embodiments of the present invention are described below based on the drawings.

[ 1. Electric work machine ]

Fig. 1 is a side view showing a schematic configuration of a hydraulic excavator 1 which is an example of an electric working machine according to the present embodiment. The hydraulic excavator 1 includes a lower traveling structure 2, a work implement 3, and an upper revolving structure 4.

Here, in fig. 1, the direction is defined as follows. First, the direction in which the lower traveling body 2 is traveling straight is referred to as the front-rear direction, one of the directions is referred to as the front direction, and the other direction is referred to as the rear direction. In fig. 1, the travel motor 22 side is shown as "front" with respect to the blade 23 as an example. The lateral direction perpendicular to the front-rear direction is set as the left-right direction. At this time, the left side is set to "left" and the right side is set to "right" as viewed from an operator (operator, driver) seated in the operator seat 41a. The gravitational direction perpendicular to the front-rear direction and the left-right direction is defined as the up-down direction, the upstream side in the gravitational direction is defined as "up", and the downstream side is defined as "down".

The lower traveling body 2 includes a pair of left and right crawler belts 21 and a pair of left and right traveling motors 22. Each travel motor 22 is a hydraulic motor. The left and right travel motors 22 can drive the left and right crawler belts 21, respectively, to advance and retract the hydraulic excavator 1. A blade 23 and a blade cylinder 23a for performing a land leveling operation are provided on the lower traveling body 2. The blade cylinder 23a is a hydraulic cylinder that rotates the blade 23 in the up-down direction.

Work implement 3 includes boom 31, arm 32, and bucket 33. By independently driving the boom 31, the arm 32, and the bucket 33, an excavating operation of sand or the like can be performed.

Boom 31 is turned by boom cylinder 31 a. The base end portion of the boom cylinder 31a is supported by the front portion of the upper revolving unit 4, and the boom cylinder 31a is telescopically movable. Arm 32 is rotated by arm cylinder 32 a. The base end of arm cylinder 32a is supported by the front end of boom 31, and arm cylinder 32a is telescopically movable. The bucket 33 is rotated by a bucket cylinder 33 a. The base end of the bucket cylinder 33a is supported by the front end of the arm 32, and the bucket cylinder 33a is telescopically movable. Boom cylinder 31a, arm cylinder 32a, and bucket cylinder 33a are each composed of a hydraulic cylinder.

The upper revolving structure 4 is configured to be able to revolve with respect to the lower traveling structure 2 via a revolving bearing (not shown). An operating unit 41, a turntable 42, a swing motor 43, an engine room 44, and the like are disposed on the upper swing body 4. The upper revolving structure 4 is revolved through a revolving bearing by driving a revolving motor 43 of a hydraulic motor.

A plurality of hydraulic pumps 71 (see fig. 2) are arranged in the upper revolving unit 4. Each hydraulic pump 71 is driven by an electric motor 61 (see fig. 2) inside the engine room 44. Each hydraulic pump 71 supplies hydraulic oil (pressure oil) to hydraulic motors (e.g., the left-right travel motor 22 and the swing motor 43) and hydraulic cylinders (e.g., the blade cylinder 23a, the boom cylinder 31a, the arm cylinder 32a, and the bucket cylinder 33 a). The hydraulic motor and the hydraulic cylinder that are driven by the hydraulic oil supplied from any hydraulic pump 71 are collectively referred to as a hydraulic actuator 73 (see fig. 2).

The operator seat 41a is disposed in the operator 41. Various levers 41b are disposed around the operator's seat 41a. The hydraulic actuator 73 is driven by an operator sitting on the operator seat 41a and operating the lever 41b. This enables running of the lower running body 2, land leveling by the blade 23, excavation by the work implement 3, turning of the upper turning body 4, and the like.

A battery 53 is mounted on the upper revolving structure 4. The battery 53 is constituted by, for example, a lithium ion battery that outputs a high voltage, and is used for driving the electric motor 61. Further, an unshown power feeding port is provided in the upper revolving unit 4. The power supply port and the external power supply 51 are connected via a power supply cable 52. Thereby, the battery 53 can also be charged.

In addition, when the lower traveling body 2, the work implement 3, and the upper revolving unit 4 are collectively referred to as the machine body BA, the machine body BA may be driven by both electric-driven equipment and hydraulic equipment. That is, the body BA may include an electric travel motor, an electric cylinder, an electric swing motor, and the like in addition to the hydraulic devices such as the hydraulic actuator 73.

[ 2. Control System and Structure of Hydraulic System ]

Fig. 2 is a block diagram schematically showing a control system of the hydraulic excavator 1 and a configuration of the hydraulic system. In fig. 2, the arrow of the broken line indicates the transmission path of the probe signal. In addition, the solid arrows indicate the transmission paths of the control signals (commands). The hydraulic excavator 1 includes an electric motor 61. The electric motor 61 is driven by electric power supplied from the battery 53.

The rotation speed of the electric motor 61 is detected by a rotation speed detection sensor 61a. That is, the hydraulic excavator 1 includes a rotation speed detection sensor 61a that detects the rotation speed of the electric motor 61. Information of the rotational speed of the electric motor 61 detected by the rotational speed detection sensor 61a is input to the ECU80 described later.

The hydraulic excavator 1 includes a charger 62. The charger 62 converts an ac voltage supplied from the external power supply 51 via the power supply cable 52 (see fig. 1) into a dc voltage. The direct-current voltage (electric power) output from the charger 62 is supplied to the battery 53. The battery 53 is charged by supplying electric power from the external power source 51 to the battery 53 via the charger 62. That is, the hydraulic excavator 1 includes the charger 62 that supplies electric power from the external power supply 51 to the battery 53 to charge the battery 53.

The hydraulic excavator 1 includes an inverter 63. The inverter 63 converts the dc voltage supplied from the battery 53 into an ac voltage and supplies the ac voltage to the electric motor 61. Thereby, the electric motor 61 rotates. The ac voltage (current) is supplied from the inverter 63 to the electric motor 61 based on a rotation command (control signal) output from the ECU 80.

The electric power supplied from the battery 53 to the electric motor 61 passes through the first circuit E1. The inverter 63 is located between the battery 53 and the electric motor 61 in the first circuit E1. In addition, the electric power supplied from the charger 62 to the battery 53 passes through the second circuit E2. The second circuit E2 merges at a merging portion Ec between the battery 53 and the inverter 63 in the first circuit E1. Therefore, the electric power output from the charger 62 is supplied to the battery 53 via the second circuit E2 and the junction Ec. Specifically, the hydraulic excavator 1 includes: a first circuit E1 for supplying electric power from the battery 53 to the electric motor 51; and a second circuit E2 connected to the charger 62 and connected to the first circuit E1 at a junction Ec.

The hydraulic excavator 1 further includes a relay 64. The relay 64 is located between the junction Ec and the battery 53 in the first circuit E1. Then, the relay 64 switches the first circuit E1 between a connected state (in which the battery 53 and the inverter 63 are electrically connected) and a disconnected state (in which the battery 53 and the inverter 63 are electrically disconnected) based on the control of the ECU 80. The relay 64 detects the connection state or the disconnection state, and outputs the detection signal to the ECU 80. Thus, ECU80 can manage the connection time or disconnection time of relay 64 based on the detection signal.

The hydraulic excavator 1 further includes a hydraulic system 70. The hydraulic system 70 includes a hydraulic pump 71, a control valve 72, and a hydraulic actuator 73.

The hydraulic pump 71 is connected to a rotation shaft (output shaft) of the electric motor 61, and is driven by the rotation of the electric motor 61. The hydraulic pump 71 is, for example, a variable displacement pump, but may be a fixed displacement pump. The hydraulic pump 71 is provided in plurality as described above, but only one hydraulic pump 71 is illustrated in fig. 2 as an example. The hydraulic pump 71 supplies hydraulic oil in a hydraulic oil tank (not shown) as hydraulic oil to the hydraulic actuator 73 via the control valve 72. Thereby, the hydraulic actuator 73 is driven. The control valve 72 is a direction switching valve that controls the flow direction and flow rate of the pressure oil supplied from the hydraulic pump 71 to the hydraulic actuators 73, and is provided corresponding to each of the hydraulic actuators 73.

Thus, the hydraulic excavator 1 includes the hydraulic system 70, and the hydraulic system 70 includes the hydraulic pump 71 driven by the electric motor 61 and the hydraulic actuator 73 to which the hydraulic pump 71 supplies the hydraulic oil.

The hydraulic excavator 1 further includes an ECU (Electronic Control Unit; electronic control unit) 80. The ECU80 is a control unit that controls each part of the hydraulic excavator 1, and is configured to include, for example, a CPU (Central Processing Unit) and a storage unit. ECU80 generates a rotation command of electric motor 61 and supplies the rotation command to inverter 63.

In addition, detection signals from the respective parts of the hydraulic excavator 1 are input to the ECU 80. For example, sensors (not shown) for detecting whether or not the operation state of the electric motor 61, the charger 62, the inverter 63, and the battery 53 includes abnormality are incorporated in the respective sensors, and detection signals from the sensors are input to the ECU 80. Thus, the ECU80 can recognize the operation states of the electric motor 61, the charger 62, the inverter 63, and the battery 53, respectively, based on the detection signals.

For example, the ECU80 can recognize the time of driving the electric motor 61 as the operation time of the electric motor 61 based on a detection signal from a sensor built in the electric motor 61. In addition, the ECU80 can recognize the time at which the charger 62 operates (for example, the charging time of the battery 53) based on the detection signal from the sensor built in the charger 62. The ECU80 can identify the time when the battery 53 is operated (for example, the charge time and the discharge time of the battery 53) based on the detection signal from the sensor incorporated in the battery 53, and can also identify the remaining amount (charge amount) of the battery 53.

The ECU80 stores and manages the first operation information and the second operation information in a storage unit in the ECU 80. The first operation information is information indicating a physical quantity of the operation state of the electric motor 61, and includes, for example, the operation time of the electric motor 61 described above. Further, the first operation information may also include information of the rotational speed of the electric motor 61 detected by the rotational speed detection sensor 61a. On the other hand, the second operation information is information indicating a physical quantity of the operation state of the battery 53, and includes, for example, the operation time (charge time+discharge time) of the battery 53 described above. In addition, the second operation information may also include the remaining amount of the battery 53.

In this way, the hydraulic excavator 1 includes the ECU80 as the control unit that manages the physical quantity indicating the operation state of the electric motor 61 as the first operation information based on the output signal of the electric motor 61, and manages the physical quantity indicating the operation state including the charge and discharge of the battery 53 as the second operation information based on the output signal of the battery 53.

The hydraulic excavator 1 further includes an output unit 90. The output unit 90 outputs the first operation information and the second operation information managed by the ECU 80. Such an output section 90 includes a display section 91 and a communication section 92.

The display unit 91 is configured by, for example, a liquid crystal display device, and displays the first operation information and the second operation information under the control of the ECU 80. That is, the output unit 90 includes a display unit 91 that displays the first operation information and the second operation information. The communication unit 92 is an interface for communicating with an external terminal, and is configured to include an antenna, a transceiver circuit, and the like.

Further, although not shown, the hydraulic excavator 1 is provided with: a working oil temperature sensor for detecting the temperature of the working oil; and a cooling water temperature sensor that detects the temperature of cooling water flowing through a cooling system for cooling the electric motor 61 or the like.

Fig. 3 shows an example of display in the display section 91. As shown in the figure, the display unit 91 displays the respective information 101 to 103 of the working oil temperature detected by the working oil temperature sensor, the remaining amount of the battery 53, and the temperature of the cooling water detected by the cooling water temperature sensor. The display unit 91 displays the operation time T1 of the electric motor 61 as first operation information together with the icon M1 indicating the electric motor 61, and displays the operation time T2 of the battery 53 as second operation information together with the icon M2 indicating the battery 53. In the example of the figure, the operation time T1 is shown as "300H", and the operation time T2 is shown as "500H". Further, "H" represents hours (Hour) (hereinafter, the same).

As in the present embodiment, ECU80 manages a physical quantity indicating the operation state of electric motor 61 (for example, operation time T1 of electric motor 61) as first operation information, and a physical quantity indicating the operation state including charge and discharge of battery 53 (for example, operation time t2=charge time+discharge time) as second operation information. In this case, the output unit 90 outputs the first operation information, and an operator or the like (an operator, a surrounding operator, a system manager, or the like) can perform maintenance (maintenance check) of the hydraulic system 70 (for example, the hydraulic pump 71) at an appropriate timing based on the output first operation information. Further, the second operation information is output by the output unit 90, so that the operator or the like can perform maintenance of the battery 53 at an appropriate timing in which not only degradation during discharging but also degradation during charging of the battery 53 is considered, that is, at an appropriate timing independent of the maintenance timing of the hydraulic system 70, based on the second operation information, and can replace the battery 53 as needed.

In particular, the physical quantity representing the operation state of the electric motor 61 includes the operation time T1 of the electric motor 61. The hydraulic pump 71 is driven by the electric motor 61, so the operation time of the hydraulic system 70 including the hydraulic pump 71 can be regarded as almost the same as the operation time of the electric motor 61. Therefore, the ECU80 manages the operation time T1 of the electric motor 61 as the first operation information, and when the first operation information is output from the output unit 90, the operator or the like can perform maintenance of the hydraulic system 70 at an appropriate timing based on the first operation information, that is, the operation time of the electric motor 61.

In addition, the physical quantity indicating the operation state of the battery 53 includes the charge time and the discharge time of the battery 53. In this case, when the output unit 90 outputs the second operation information, the operator or the like can perform maintenance of the battery 53 at an appropriate timing based on the sum of the charge time and the discharge time of the battery 53. That is, maintenance of the battery 53 can be performed at an appropriate timing in which not only degradation in discharging but also degradation in charging of the battery 53 is considered.

The physical quantity indicating the operation state of the battery 53 is not limited to the sum of the charge time and the discharge time of the battery 53. For example, the sum of the total charge amount (absolute value) obtained by integrating the charge amount in the predetermined period of the battery 53 for each predetermined period and the total discharge amount (absolute value) obtained by integrating the discharge amount in the predetermined period of the battery 53 for each predetermined period may be used as the physical quantity indicating the operation state of the battery 53. In this case, when the output unit 90 outputs the second operation information, the operator or the like can perform maintenance of the battery 53 at an appropriate timing in which not only degradation due to discharging but also degradation due to charging of the battery 53 is considered, based on the output second operation information, that is, the sum of the total charge amount and the total discharge amount of the battery 53.

In the present embodiment, the output unit 90 includes a display unit 91 that displays the first operation information and the second operation information. Thus, for example, the operator can easily determine the timing of performing maintenance of the hydraulic system 70 by observing the first operation information (for example, the operation time T1) displayed on the display unit 91, and can easily determine the timing of performing maintenance of the battery 53 by observing the second operation information (for example, the operation time T2) displayed on the display unit 91.

In the present embodiment, the output unit 90 includes a communication unit 92. In this configuration, the ECU80 can output the first operation information and the second operation information to the external terminal via the communication unit 92, and can identify the first operation information and the second operation information to the system manager using the terminal. Thus, the manager can appropriately manage the maintenance timing of the hydraulic system 70 based on the first operation information, and can appropriately manage the maintenance timing in which degradation caused by discharging and charging of the battery 53 is considered based on the second operation information.

The ECU80 may determine whether or not at least one of the physical quantity managed as the first operation information and the physical quantity managed as the second operation information reaches a predetermined value, and when the predetermined value is reached, may cause the display unit 91 to display information that the predetermined value has been reached. For example, fig. 4 shows another example of the display in the display section 91. The following examples are shown in this figure: when the operation time T1 of the electric motor 61 reaches a first predetermined value (for example, 600H), the display unit 91 causes the operation time T1 to flash, thereby reporting that the operation time T1 reaches the first predetermined value. In this figure, when the operation time T2 of the battery 53 reaches a second predetermined value (for example, 1000H), the display unit 91 causes the operation time T2 to flash and display, thereby reporting that the operation time T2 reaches the second predetermined value.

In this way, by controlling the display of the display unit 91 by the ECU80, the operator can immediately grasp that the physical quantity managed as the first operation information or the second operation information reaches the predetermined value by observing the display unit 91, and can easily recognize that at least one of the hydraulic system 70 and the battery 53 is at the time when maintenance is required. Thus, the operator can quickly perform appropriate maintenance such as inspection of the hydraulic pump 71 and exchange of the battery 53.

Fig. 4 shows an example in which the operation time T1 and the operation time T2 of the electric motor 61 reach the respective predetermined values (the first predetermined value and the second predetermined value) at the same time, but they do not necessarily reach the same time. That is, when at least one of the operation time T1 and the operation time T2 reaches a predetermined value, the ECU80 may cause the display unit 91 to flash and display the operation time reaching the predetermined value, thereby reporting that the predetermined value has been reached.

However, the ECU80 preferably manages, as the first operation information, a physical quantity indicating an operation state of the electric motor 61 in a state where the rotation speed of the electric motor 61 detected by the rotation speed detection sensor 61a exceeds a prescribed value (for example, 10 rotations/min). In this case, the ECU80 displays, as the operation time T1 of the electric motor 61, the time when the electric motor 61 is operated in a state where the rotation speed of the electric motor 61 exceeds a predetermined value on the display screen of the display unit 91 shown in fig. 3 and 4.

By managing the first operation information as described above, the ECU80 can exclude, from the first operation information of the electric motor 61, for example, an operation time in a state where the electric motor 61 is rotated at a rotational speed (for example, an ultra low speed) equal to or lower than the predetermined value and is not considered to be substantially operated, and can manage, as the first operation information, an operation time in a state where the electric motor 61 is considered to be substantially rotated at a rotational speed exceeding the predetermined value. This can improve the management accuracy of the maintenance timing of the electric motor 61 based on the first operation information.

[ 3 ] method for acquiring physical quantity indicating the operating state of battery ]

The driving modes of the hydraulic excavator 1 of the present embodiment include a charging mode and a battery mode. The charging mode is an operation mode in which the battery 53 is charged by the charger 62. On the other hand, the battery mode is an operation mode in which the electric motor 61 is driven by the electric power of the battery 53.

Fig. 5 schematically shows an example of the state (connection state/disconnection state) of the relay 64, the operation state of the electric motor 61, the operation state of the charger 62, and the operation state of the battery 53 in each of the charging mode and the battery mode. When the hydraulic shovel 1 is driven in both the charging mode and the battery mode, the battery 53 is charged by the operation of the charger 62 in the charging mode, so the operation time (2) of the charger 62 and the charging time (3) of the battery 53 are the same. On the other hand, in the battery mode, since the battery 53 is discharged due to the operation of the electric motor 61, the operation time (1) of the electric motor 61 is the same as the discharge time (4) of the battery 53. Therefore, the sum of the charging time (3) and the discharging time (4) of the battery 53 is equal to the sum of the operating time (2) of the charger 62 and the operating time (1) of the electric motor 61. That is, the physical quantity (charge time (3) of the battery 53) +discharge time (4) of the battery 53), which represents the operation state including the charge and discharge of the battery 53, is the sum of the operation time (2) of the charger 62 and the operation time (1) of the electric motor 61.

Therefore, when the hydraulic excavator 1 is driven in the charge mode or the battery mode as described above, the ECU80 can easily acquire and manage the physical quantity (charge time (3) +discharge time (4)) indicating the operation state of the battery 53 by managing the sum of the operation time (2) of the charger 62 and the operation time (1) of the electric motor 61.

[ 4 ] other method for acquiring physical quantity indicating the operating state of battery ]

The drive mode of the hydraulic shovel 1 may include a power supply combined mode in addition to the charge mode and the battery mode described above. The power-source combined mode is a mode in which the electric motor 61 is driven by electric power supplied from at least one of the external power source 51 and the battery 53.

Fig. 6 schematically shows an example of the state (connection state/disconnection state) of the relay 64, the operation state of the electric motor 61, the operation state of the charger 62, and the operation state of the battery 53 in each of the charging mode, the battery mode, and the power supply combined mode. When the hydraulic shovel 1 is driven in the 3 drive modes of the charge mode, the battery mode, and the power supply combined mode, the physical quantity (charge time (D) of the battery 53) +discharge time (E) of the battery 53), which indicates the operation state including the charge and discharge of the battery 53, is not the sum of the operation time (C) of the charger 62 and the operation time (B) of the electric motor 61, and the same relationship as in fig. 5 cannot be obtained.

However, although the battery 53 is charged or discharged in the charging mode, the battery mode, or the power supply combined mode, the charging or discharging is performed in a state where the relay 64 is connected. Therefore, the sum of the charge time (D) and the discharge time (E) of the battery 53 is equal to the connection time (a) of the relay 64. That is, the physical quantity (charge time (D) of the battery 53) +discharge time (E) of the battery 53), which indicates the operation state including the charge and discharge of the battery 53, is the connection time (a) of the relay 64.

Therefore, when the hydraulic shovel 1 is driven in the charge mode, the battery mode, or the power supply combined mode as described above, the ECU80 can easily acquire and manage the physical quantity (charge time (D) +discharge time (E)) indicating the operation state of the battery 53 by managing the connection time (a) of the relay 64.

In fig. 5, the relationship between the charging time (D) +discharging time (E) of the battery 53 and the connection time (a) of the relay 64 can be described. That is, when the hydraulic excavator 1 is driven in the 2 driving modes of the charging mode and the battery mode, the relay 64 is in the connected state in both the charging mode and the discharging mode, so that the sum of the charging time (3) and the discharging time (4) of the battery 53 is equal to the connection time (5) of the relay 64 in fig. 5. Therefore, even when the hydraulic excavator 1 is driven in two drive modes (the charge mode or the battery mode) as shown in fig. 5, the above-described effect can be obtained that the ECU80 can easily obtain and manage the physical quantity indicating the operation state of the battery 53 by managing the connection time of the relay 64.

While the hydraulic excavator as the construction machine has been described as an example as an electric working machine, the working machine is not limited to the hydraulic excavator, and may be another construction machine such as a wheel loader, or an agricultural machine such as a combine harvester or a tractor.

While the embodiments of the present invention have been described above, the scope of the present invention is not limited to the above, and the present invention can be extended or modified without departing from the scope of the present invention.

Industrial applicability

The present invention can be used in, for example, a working machine such as a construction machine and an agricultural machine.

Description of the reference numerals

1 … hydraulic excavator (electric working machine); 51 … external power source; 53 … cell; 61 … electric motor; 62 … charger; 61a … rotation speed detecting sensor; 64 … relay; 70 … hydraulic system; 71 … hydraulic pump; 73 … hydraulic actuator; 80 … ECU (control unit); 90 … output; 91 … display section; e1 … first circuit; e2 … second circuit; ec … junction.

Claims

1. An electric working machine, comprising:

a charger that supplies power from an external power source to a battery to charge the battery;

an electric motor driven by electric power supplied from the battery;

a hydraulic system including a hydraulic pump driven by the electric motor and a hydraulic actuator supplied with pressure oil by the hydraulic pump;

a control unit that manages, as first operation information, a physical quantity indicating an operation state of the electric motor, and manages, as second operation information, a physical quantity indicating an operation state including charge and discharge of the battery; and

and an output unit configured to output the first operation information and the second operation information.

2. The electric work machine of claim 1, wherein the electric power generator is configured to generate the electric power,

the physical quantity indicative of the operating state of the electric motor includes an operating time of the electric motor.

3. The electric work machine according to claim 1 or 2, wherein,

the physical quantity representing the operating state of the battery includes a sum of a charge time and a discharge time of the battery.

4. The electric work machine according to any one of claim 1 to 3, wherein,

the output unit includes a display unit that displays the first operation information and the second operation information.

5. The electric work machine of claim 4, wherein the electric power generator is configured to generate the electric power,

the control unit determines whether or not at least one of a physical quantity managed as the first operation information and a physical quantity managed as the second operation information has reached a predetermined value, and causes the display unit to display information that has reached the predetermined value when the predetermined value has been reached.

6. The electric work machine according to any one of claims 1 to 5, wherein,

and a rotation speed detection sensor for detecting the rotation speed of the electric motor,

the control unit manages, as the first operation information, a physical quantity indicating an operation state of the electric motor in a state where the rotational speed of the electric motor detected by the rotational speed detection sensor exceeds a predetermined value.

7. The electric work machine according to any one of claims 1 to 6, wherein,

the drive mode of the electric work machine includes:

a charging mode in which the battery is charged by the charger; and

a battery mode in which the electric motor is driven by electric power of the battery,

the physical quantity representing the operation state including the charge and discharge of the battery is the sum of the operation time of the charger and the operation time of the electric motor.

8. The electric work machine according to any one of claims 1 to 7, further comprising:

a first circuit for supplying electric power from the battery to the electric motor;

the second circuit is connected with the charger and is converged with the first circuit at a converging part;

a relay that is located between the junction and the battery in the first circuit, switches the first circuit between a connected state and a disconnected state,

the physical quantity representing the operation state including the charge and discharge of the battery is the connection time of the relay.